The present invention relates to a method of determining the electrical properties of an electrical device, wherein the method comprises the following steps: taking of a measurement of an electrical measured quantity at one or more brought-out electrical connections of each of several equipotential bodies of the electrical device.
An example of an electrical device with electrical properties to be determined by the method according to the invention is for example described in DE 199 04 751 C1. Here, an equipotential body is understood to mean a part of the electrical device, the surface of which forms an equipotential surface at least when no alternating voltage and no alternating field are applied to the equipotential surface. At the same time the equipotential body and therefore also its surface may be partly or wholly embedded in other parts of the electrical device, thus creating an internal surface of the equipotential body which is at least partly invisible from the surroundings of the electrical device. Typically, the equipotential body is a two-dimensional object, so that its length amounts to at least a hundred times, preferably a thousand times its thickness. The individual equipotential bodies of the electrical device may—in comparison with one another—have quite different forms. An equipotential body may have a shape which is disc-like, rectangular, meandering, spiral, star-like, multi-star-like, grid-like and/or branched in some other way. Typically the equipotential body is made of a doped semiconductor or of a metal such as copper, silver, gold or aluminum or of a metal alloy. Here, “connection” means a part of the equipotential body accessible from a surface of the electrical device.
EP 0 853 242 A 1 describes a method for the testing of circuit boards in which several nets of a circuit board are short-circuited, and the nets short-circuited with one another are tested together for short-circuits against other nets.
10 EP 0 508 062 A 1 defines a field measurement method in which a conductor configuration is subjected to an electrical field, and at least one electrical potential forming in the conductor configuration due to the electrical field is tapped by measuring probes at the individual test points, and compared with the potential of other test points and/or with a reference.
EP 0 772 054 A2 discloses a method in which firstly, in a first measuring process, a first conductor configuration is tested by means of a field measurement, wherein complex conductances for the individual nets are determined with the aid of the field measurement. In the subsequent measuring processes of further conductor configurations, the complex conductances of the conductor paths are measured and compared with the complex conductances determined previously.
WO 2006/133808 A1 relates to a method in which non-componented, extensive circuit boards are tested using a finger tester. In this method, the circuit boards are tested divided into several segments, wherein conductor paths which extend beyond a segment are tested by means of capacitive measurement of the end points located in the segment concerned.
U.S. Pat. No. 5,744,964 discloses a device for the measurement of conductor configurations in which the individual nets of the conductor configurations may be measured by means of a resistance measurement or a capacitance measurement. In the capacitance measurement, two nets independent of one another are each contacted by a test probe, and the capacitance between these two test probes is measured.
Described in DE 34 08 704 A 1 is a device for the testing of circuit configurations in which nets of the circuit configuration are tested by means of a capacitive measurement. The capacitive measurement is effected with reference to a conductive board which is separated from the circuit configuration by means of a dielectric, insulating board.